Material Attractiveness and Categorization

Activities at the Nuclear Regulatory

Commission

Tim Harris NRC Office of Nuclear Security

and Incident Response

February 2014

Background

• NRC is in the process of revising its regulations for physical protection of

special nuclear material (SNM)

– Revise nuclear material categorization table

– Put over 50 Orders into regulations – accumulated since 9/11/01

• NRC has a legislative mandate to make available for public comment its

proposed regulatory changes

• Commission directed NRC staff to conduct “enhanced” stakeholder

outreach, including with international partners

• Revisions to INFCIRC/225 recently issued– want to ensure consistency

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Current NRC Approach

• Categorization table (I, II, III; Pu, U-235, U-233, irrad fuel)

Nearly identical to Categorization Table in INFCIRC/225/Rev. 5

Cat I = “Formula Quantity of Strategic Special Nuclear Material”

Cat II = “SNM of Moderate Strategic Significance”

Cat III = “SNM of Low strategic significance”

Based on threat of IND

Approximately 50 yrs old

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Material Form

Category

I II IIIe

1. Plutoniuma Unirradiatedb 2 kg or more Less than 2 kg but

more than 500 g

500 g or less

2. Uranium -235c

Unirradiatedb

Uranium enriched to 20 pct U235 or more

5 kg or more Less than 5 kg but

more than 1 kg

1 kg or less

Uranium enriched to 10 pct U235 but less

than 20 pct.

10 kg or more Less than 10 kg

Uranium enriched above natural, but less

than 10 pct U235

10 kg or more

3. Uranium-233 Unirradiatedb 2 kg or more Less than 2 kg but

more than 500 g

500 g or less

Current Table - App. M to 10 CFR Part

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Current NRC Approach (cont.)

• Two-factor consideration - type and quantity

– Ease of use

– Insufficient to provide risk-informed, graded approach

– Led to lack of consistency and transparency in regulations

• 5 kg high enriched uranium (HEU) metal vs. 5 kg of HEU in soil

• “Right-size” security regulations by adding attractiveness to

special nuclear material (SNM) categorization

– Make appropriate to individual forms of SNM

– Restore regulatory predictability / clarity

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INFCIRC/225/Rev. 5 Attractiveness

Factors

• “…the basis for a graded approach…depends on the

type of nuclear material (e.g. plutonium and

uranium), isotopic composition (i.e. content of fissile

isotopes), physical and chemical form, degree of

dilution, radiation level, and quantity.

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Material Attractiveness Factors Considered

• Factors

– Form (metals, compounds, solutions, in a matrix)

– Weight percent of SNM in compound (dilution factor)

• Calculations based on total weight of bulk material or item – should not include

cladding material that is easily removed

– Radiation level – considering changes

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Uranium-235

Nuclear Material Attractiveness Level

Pure Products

Metals, simple compounds (≥20 wt %) (compounds that can be converted to metal in a

single step)

A

High-Grade Materials

Complex compounds (≥20 wt %) (compounds that cannot be converted to metal in a

single step; solutions (≥25 g/l)

B

Low-Grade Materials

Metals and compounds (≥1 wt % and <20 wt %); solutions (≥1 g/l and <25 g/l)

C

All Other Materials

Uranium (<10% U-235); highly irradiated material (≥1000 R/h @ 1 m); metals and

compounds (<1 wt %); solutions (<1 g/l)

D

Initial Attractiveness Levels Considered

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Plutonium and Uranium-233

Nuclear Material Attractiveness Level

Pure Products

Metals (≥20 wt %), simple compounds (≥20 wt %) (compounds that can be converted to

metal in a single step)

A

High-Grade Materials

Complex compounds (≥20 wt %) (compounds that cannot be converted to metal in a

single step; solutions (≥25 g/l)

B

Low-Grade Materials

Metals and compounds (≥1 wt % and <20 wt %); solutions (≥1 g/l and <25 g/l); Pu (≥80

% Pu-238)

C

All Other Materials

Uranium (<6% U-233); highly irradiated material (≥1000 R/h @ 1 m); metals and

compounds (<1 wt %); solutions (<1 g/l)

D

Initial Attractiveness Levels Considered

Los Alamos Study

• Logic Model

– Acquisition Module

– Processing Module

– Weapons Module

– Degradation Model

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Stakeholder Interaction

• Other USG Agencies

• Industry

• Non-Governmental Organizations

• Foreign Governments

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Initial Stakeholder Feedback

• Generally Consistent with INFCIRC/225

• Technically Sound

• Concern over complexity of the approach

• Concern over metals and compounds having

different treatments

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Uranium-235

Nuclear Material Attractiveness

Level

Cat I Cat II Cat III

High-Grade Materials

Metals and compounds (≥20 wt %), solutions (≥25 g/l)

A ≥5 kg ≥1 kg

<5 kg

≥RQ

<1 kg

Low-Grade Materials

Metals and compounds (≥1 wt % and <20 wt %);

solutions (≥1 g/l and <25 g/l)

B N/A ≥25 kg? ≥RQ

<25 kg?

All Other Materials

Uranium (<10% U-235); highly irradiated material

(≥1000 R/h @ 1 m); metals and compounds (<1 wt

%); solutions (<1 g/l)

C N/A N/A ≥RQ

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Revised Table

Plutonium and Uranium-233

Nuclear Material Attractiveness

Level

Cat I Cat II Cat III

High-Grade Materials

Metals and compounds (≥20 wt %); solutions (≥25

g/l)

A ≥2 kg ≥0.4 kg

<2 kg

≥RQ

<0.4 kg

Low-Grade Materials

Metals and compounds (≥1 wt % and <20 wt %);

solutions (≥1 g/l and <25 g/l); Pu (≥80 % Pu-238)

B N/A ≥10 kg? ≥RQ

<10 kg?

All Other Materials

Uranium (<6% U-233); highly irradiated material

(≥1000 R/h @ 1 m); metals and compounds (<1 wt

%); solutions (<1 g/l)

C N/A N/A ≥RQ

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Revised Table

Continuing Feedback

• Concern about changes from higher to lower

categories (Perceived as significant reduction in

security)

• Concern about large quantities of HEU or Pu in

dilute materials

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Need to Retain Current Categorization

• Concern about changes from higher to lower categories

(Perceived as significant reduction in security)

• Concern about large quantities of HEU or Pu in dilute

materials

• Need to demonstrate “High Assurance of Adequate

Protection”

• Potential consequence linked to the Category

• Protection Strategies must be informed by the risk

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Current Approach

• Maintain existing categories (allows emphasis on

potential consequences)

• Allow for alternative security measures for levels of

dilution (dilution identified in INFCIRC/225 and

serves as a proxy for processing difficulty)

– Moderate -- <20 weight percent and >= 1 weight percent

– Very -- < 1 weight percent

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Protection Strategies – non-dilute

• Cat I

– Containment

• Cat II

– Immediate Detection with Pursuit and Recovery

• Cat III

– Detection and Recovery

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Protection Strategies – moderately dilute

• Cat I

– Immediate Detection with Pursuit and Recovery

• Cat II

– Prompt Detection and Response and Recovery

• Cat III

– Detection and Recovery

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Protection Strategies – very dilute

• Cat I, II, III

– Detection and Recovery

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Conclusions

• Approach “right sizes” security requirements

• Provides incentives for dilution, which makes

material less attractive and adds difficulty to the

adversary’s acquisition of material and delay to

an adversary’s ability to use material, providing

more defense in depth

• Maintains high assurance of adequate protection

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